Remove dead code: 64-bit protobuf types never used in 7 years (#9471)

esphome/components/api/proto.h

@@ -175,23 +175,7 @@ class Proto32Bit {
   const uint32_t value_;
 };
 
-class Proto64Bit {
+// NOTE: Proto64Bit class removed - wire type 1 (64-bit fixed) not supported
- public:
-  explicit Proto64Bit(uint64_t value) : value_(value) {}
-  uint64_t as_fixed64() const { return this->value_; }
-  int64_t as_sfixed64() const { return static_cast<int64_t>(this->value_); }
-  double as_double() const {
-    union {
-      uint64_t raw;
-      double value;
-    } s{};
-    s.raw = this->value_;
-    return s.value;
-  }
-
- protected:
-  const uint64_t value_;
-};
 
 class ProtoWriteBuffer {
  public:
@@ -258,20 +242,10 @@ class ProtoWriteBuffer {
     this->write((value >> 16) & 0xFF);
     this->write((value >> 24) & 0xFF);
   }
-  void encode_fixed64(uint32_t field_id, uint64_t value, bool force = false) {
+  // NOTE: Wire type 1 (64-bit fixed: double, fixed64, sfixed64) is intentionally
-    if (value == 0 && !force)
+  // not supported to reduce overhead on embedded systems. All ESPHome devices are
-      return;
+  // 32-bit microcontrollers where 64-bit operations are expensive. If 64-bit support
-
+  // is needed in the future, the necessary encoding/decoding functions must be added.
-    this->encode_field_raw(field_id, 1);  // type 1: 64-bit fixed64
-    this->write((value >> 0) & 0xFF);
-    this->write((value >> 8) & 0xFF);
-    this->write((value >> 16) & 0xFF);
-    this->write((value >> 24) & 0xFF);
-    this->write((value >> 32) & 0xFF);
-    this->write((value >> 40) & 0xFF);
-    this->write((value >> 48) & 0xFF);
-    this->write((value >> 56) & 0xFF);
-  }
   void encode_float(uint32_t field_id, float value, bool force = false) {
     if (value == 0.0f && !force)
       return;
@@ -337,7 +311,7 @@ class ProtoMessage {
   virtual bool decode_varint(uint32_t field_id, ProtoVarInt value) { return false; }
   virtual bool decode_length(uint32_t field_id, ProtoLengthDelimited value) { return false; }
   virtual bool decode_32bit(uint32_t field_id, Proto32Bit value) { return false; }
-  virtual bool decode_64bit(uint32_t field_id, Proto64Bit value) { return false; }
+  // NOTE: decode_64bit removed - wire type 1 not supported
 };
 
 class ProtoSize {
@@ -662,33 +636,8 @@ class ProtoSize {
     total_size += field_id_size + varint(value);
   }
 
-  /**
+  // NOTE: sint64 support functions (add_sint64_field, add_sint64_field_repeated) removed
-   * @brief Calculates and adds the size of a sint64 field to the total message size
+  // sint64 type is not supported by ESPHome API to reduce overhead on embedded systems
-   *
-   * Sint64 fields use ZigZag encoding, which is more efficient for negative values.
-   */
-  static inline void add_sint64_field(uint32_t &total_size, uint32_t field_id_size, int64_t value) {
-    // Skip calculation if value is zero
-    if (value == 0) {
-      return;  // No need to update total_size
-    }
-
-    // ZigZag encoding for sint64: (n << 1) ^ (n >> 63)
-    uint64_t zigzag = (static_cast<uint64_t>(value) << 1) ^ (static_cast<uint64_t>(value >> 63));
-    total_size += field_id_size + varint(zigzag);
-  }
-
-  /**
-   * @brief Calculates and adds the size of a sint64 field to the total message size (repeated field version)
-   *
-   * Sint64 fields use ZigZag encoding, which is more efficient for negative values.
-   */
-  static inline void add_sint64_field_repeated(uint32_t &total_size, uint32_t field_id_size, int64_t value) {
-    // Always calculate size for repeated fields
-    // ZigZag encoding for sint64: (n << 1) ^ (n >> 63)
-    uint64_t zigzag = (static_cast<uint64_t>(value) << 1) ^ (static_cast<uint64_t>(value >> 63));
-    total_size += field_id_size + varint(zigzag);
-  }
 
   /**
    * @brief Calculates and adds the size of a string/bytes field to the total message size

script/api_protobuf/api_protobuf.py

@@ -313,6 +313,37 @@ class TypeInfo(ABC):
 
 TYPE_INFO: dict[int, TypeInfo] = {}
 
+# Unsupported 64-bit types that would add overhead for embedded systems
+# TYPE_DOUBLE = 1, TYPE_FIXED64 = 6, TYPE_SFIXED64 = 16, TYPE_SINT64 = 18
+UNSUPPORTED_TYPES = {1: "double", 6: "fixed64", 16: "sfixed64", 18: "sint64"}
+
+
+def validate_field_type(field_type: int, field_name: str = "") -> None:
+    """Validate that the field type is supported by ESPHome API.
+
+    Raises ValueError for unsupported 64-bit types.
+    """
+    if field_type in UNSUPPORTED_TYPES:
+        type_name = UNSUPPORTED_TYPES[field_type]
+        field_info = f" (field: {field_name})" if field_name else ""
+        raise ValueError(
+            f"64-bit type '{type_name}'{field_info} is not supported by ESPHome API. "
+            "These types add significant overhead for embedded systems. "
+            "If you need 64-bit support, please add the necessary encoding/decoding "
+            "functions to proto.h/proto.cpp first."
+        )
+
+
+def get_type_info_for_field(field: descriptor.FieldDescriptorProto) -> TypeInfo:
+    """Get the appropriate TypeInfo for a field, handling repeated fields.
+
+    Also validates that the field type is supported.
+    """
+    if field.label == 3:  # repeated
+        return RepeatedTypeInfo(field)
+    validate_field_type(field.type, field.name)
+    return TYPE_INFO[field.type](field)
+
 
 def register_type(name: int):
     """Decorator to register a type with a name and number."""
@@ -738,6 +769,7 @@ class SInt64Type(TypeInfo):
 class RepeatedTypeInfo(TypeInfo):
     def __init__(self, field: descriptor.FieldDescriptorProto) -> None:
         super().__init__(field)
+        validate_field_type(field.type, field.name)
         self._ti: TypeInfo = TYPE_INFO[field.type](field)
 
     @property
@@ -1025,10 +1057,7 @@ def calculate_message_estimated_size(desc: descriptor.DescriptorProto) -> int:
     total_size = 0
 
     for field in desc.field:
-        if field.label == 3:  # repeated
+        ti = get_type_info_for_field(field)
-            ti = RepeatedTypeInfo(field)
-        else:
-            ti = TYPE_INFO[field.type](field)
 
         # Add estimated size for this field
         total_size += ti.get_estimated_size()
@@ -1334,10 +1363,7 @@ def build_base_class(
     # For base classes, we only declare the fields but don't handle encode/decode
     # The derived classes will handle encoding/decoding with their specific field numbers
     for field in common_fields:
-        if field.label == 3:  # repeated
+        ti = get_type_info_for_field(field)
-            ti = RepeatedTypeInfo(field)
-        else:
-            ti = TYPE_INFO[field.type](field)
 
         # Only add field declarations, not encode/decode logic
         protected_content.extend(ti.protected_content)